CMF / CRF Details

CMF ID: 44

Install any type of median barrier


Prior Condition: No Prior Condition(s)

Category: Roadside

Study: Handbook of Road Safety Measures, Elvik, R. and Vaa, T., 2004

Star Quality Rating: 5 Stars
Crash Modification Factor (CMF)
Value: 1.24
Adjusted Standard Error: 0.03
Unadjusted Standard Error: 0.02
Crash Reduction Factor (CRF)
Value: -24   (This value indicates an increase in crashes)
Adjusted Standard Error: 3
Unadjusted Standard Error: 2
Crash Type: All
Crash Severity: All
Roadway Types: Principal Arterial Other
Number of Lanes: Multilane
Road Division Type: Divided
Speed Limit:
Area Type: Rural
Traffic Volume: Minimum of 20000 to Maximum of 60000
Average Traffic Volume:
Time of Day:
If countermeasure is intersection-based
Intersection Type:
Intersection Geometry:
Traffic Control:
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used:
Type of Methodology Used: Meta-analysis
Other Details
Included in Highway Safety Manual? Yes. HSM lists this CMF in bold font to indicate that it has the highest reliability since it has an adjusted standard error of 0.1 or less.
Date Added to Clearinghouse: Dec-01-2009
Comments: Countermeasure name changed from "install median guardrails on divided highways" to match HSM